The handling of elongated goods frequently is time and space-consuming. This is particularly so if the goods are to be handled for loading and unloading of a roller conveyor, to supply to goods, then, to a cutting or severing machine. Some of the goods may be individual rails, rods, or the like, whereas others may be associated in groups or held together in cassettes or other handling devices. It is equally difficult, at times, to load and unload cassettes with elongated goods, for example to transport a group of such goods in the cassettes for individual removal at a later time, or at a remote location.
Frequently, a cutter or severing machine is associated with a roller conveyor. Such cutters may, for example, be cold cutting circular saws, band saws, or other severing apparatus. The roller conveyor then supplies the elongated material or goods to the respective cutter apparatus. It is necessary to place the material on the roller conveyor and to remove, after cutting, from the supply roller conveyor left-over pieces and from the removal roller conveyor pieces which have been cut to length or size. A defined positioning of the goods with respect to the severing or cutting machine can be obtained by forming the roller conveyor in V configuration; the cutting machine itself can customarily be adjusted to fit the requirements of the goods to be cut. A frequently used arrangements is to provide a lateral register or indexing stop for the goods in advance of the cutting machine; such lateral stops may also be provided on the roller conveyor. If the goods are joined together, or all located in a cassette, the cassette itself may be transported by the roller conveyor, and, projecting ends of goods cut to predetermined length of goods while within the cassette.
Frequently, a crane or traveling hoist is used to load the roller conveyor with goods taken from storage racks located adjacent the roller conveyor. The hoist or traveling crane customarly has a support formed with projecting tines or forks. The material is removed from storage racks, transported to the roller conveyor, and any material on the roller conveyor which may be cut remainders, or cut-to-size goods, are returned to the storage racks. For easy loading and unloading, a portion of the roller conveyor, and frequently the one immediately associated with the cutting machine, is located parallel to the elongated goods within the storage area for the elongated goods. This permits movement of the goods between a storage position and a roller conveyor in a direction which extends only perpendicularly to the longitudinal extend of the goods, and moves them vertically and horizontally.
Typical storage racks for elongated goods are formed by groups of vertically staggered support brackets, shelves, or the like, and so arranged that the hoist can be moved with its forks or tines between support structures, slightly dropped below the bottom surface of the goods to be then raised, pick up the goods, and transport them to the roller conveyor. To save time and provide for efficient machine utilization, the travel times of the crane or hoist are so selected that in the region of the roller conveyor, intermediate storage and repositioning places are provided, so that, when the roller conveyor has transported a certain strip, rail bar or rod or the like, to the processing machine, the hoist can, in the meanwhile, reposition or handle other goods, for example place goods for a next working step in a temporary storage or holding position and remove previously cut material for placement on the respective shelves or brackets associated with the particular goods. Efficient operation of the system thus permits placement next to the roller conveyor material to be next worked on as soon as working of the immediately preceding material has been terminated; the previously worked-on material need then only be removed from the roller conveyor, to be replaced by the next to-be-worked-on material. The possible remainder, and any other material, can be returned to the main storage place during working on or cutting of the next one of the goods. This arrangement permits practically continuous operation of the cutting and severing machine. If sufficient material is available for working-on by the severing machine, usually sufficient time will be available so that any remnants or cut-off pieces can be returned by the crane or hoist to the appropriate storage place and to then supply the next elongated material for handling by the severing machine.
The referenced U.S. Pat. Nos. 4,372,724 and 4,488,847, by the inventor hereof, are directed to handling of elongated goods and reference is made thereto for further description of suitable storage and material handling structures.
Numerically controlled systems can be used to control the movement of a crane or hoist, support structures, and possible storage structures in relation to the operating cycle of the material severing or other machine. The numerical control can be so arranged that the structure of the storage racks and the location of the material thereon can be considered. The individual sequence of operation can be controlled, or automatically determined, and the disclosures of the referenced U.S. Pat. Nos. 4,372,724 and 4,488,847 are hereby incorporated by reference.
Various structures are so arranged that the roller conveyor can be loaded or unloaded only from one side by a carrier support, either with new material or removal of cut material. Loading from one side may be determined by register or alignment stops. If the roller conveyor can be reached only from one side by a loading crane structure or the like, support structures for goods to be handled can be provided only on one side, and the respective storage shelves, bins, or brakcets to supply the elongated rod or rail elements to the roller conveyor can be provided only on one side or, otherwise, transfer regions must be provided. This results in an undesirable utilization of storage regions, since respectively adjacent stacking racks and the like become inaccessible for stock transfer. Access from only one side can be provided through a corridor; then, for each row of storage platforms or brackets, a separate corridor or path for the crane and the like must be provided. The result is a storage structure which is undesirable from a structural point of view since any projecting brackets or shelves from upright supports are loaded only on one side, thus resulting in an unbalanced structure.
Various stacking structures for symmetrically loaded or symmetrically arranged bins, shelves or brackets, are known; use of such storage stacks or racks, however, is difficult with material support systems from the storage region to a roller conveyor since the material must be transferred from one hoist or crane in alignment with one row of brackets or bins to another crane which may be in alignment with the roller conveyor. This substantially increases the transfer time between the roller conveyor and the respective storage platform or bracket system, and substantially increases the complexity of the apparatus and the cost of the system.